Speed reference bypass and delayed speed reference, Inertia compensation – Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual User Manual
Page 149
Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
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Detailed Drive Operation Chapter 1
half to the end of the ramp (as shown in the example below). The result of the S-
curve block can be seen in parameter 43 [Ramped Spd Ref ].
Speed Reference Bypass and Delayed Speed Reference
By default, parameter 37 [Spd Ref Bypass] is linked to parameter 43 [Ramped
Spd Ref ]. However, if you wish to bypass the rest of the speed reference control
loop, [Spd Ref Bypass] can be linked to other parameters.
Parameter 45 [Delayed Spd Ref ] is delayed by one scan of the speed control loop.
Parameter 37 [Spd Ref Bypass] can be linked to [Delayed Spd Ref ] instead of
[Ramped Spd Ref ] for use in SynchLink applications. See
for more details.
Inertia Compensation
Inertia compensation is used to calculate the level of torque required due to load
inertia during speed changes. For more information on inertia compensation, see
Inertia Compensation on page 62
S Curve Time = 1.0 second
Speed
Time in Seconds
0.5 sec.
Accel Time = 5.0 seconds
Total Ramp Time = 6.0 seconds
0.5 sec.
37
43
45
Delayed Spd Ref
Link
Spd Ref Bypass
Ramped Spd Ref
Delay
One
Scan